Recurrent Pericardial Tamponade due to Sheehan Syndrome - A Rare Etiology

Cardiac tamponade is a medical emergency. The overall mortality depends on the speed of diagnosis, the treatment provided and the underlying cause of the tamponade. Untreated, the condition is rapidly and universally fatal. Pericardial effusion is not uncommon in hypothyroidism but large pericardial effusion causing tamponade as a presenting complication is very rare with only a few cases reported in literature. Central hypothyroidism constitutes very small number of patients of hypothyroidism. Thus hypopituitarism and central hypothyroidism presenting as cardiac tamponade is one rarest of rare combination with probably less than 5 cases reported in literature.

A 32 years old female patient presented with the complaints of severe weakness and fatigue of two years duration with worsening in past two months. Initial evaluation revealed severe hypotension, cold clammy extremities with distended neck veins. ECG revealed low voltage complexes and further evaluation with echocardiography revealed large pericardial effusion (20 mm anteriorly, 25 mm posteriorly) with diastolic collapse of right ventricle and right atrium. Emergency pericardiocentesis was done with aspiration of 800ml of straw colored fluid. Detailed history was taken which disclosed that she suffered similar ailment one and half year back for which pericardiocentesis was done and she was given anti-tubercular treatment for 9 months. Despite anti-tubercular therapy, her symptoms persisted in the form of generalized weakness, joint pains and other nonspecific symptoms. Investigations revealed decreased free T3-0.894pg/ml (range 1.5-5pg/ml), free T4-0.106ng/dl (range 0.95-2.25ng/ml) and TSH-0.7uIU/ml (range 0.2-5.1uIU/ml) levels indicating towards central hypothyroidism. Leading questions brought out history of amenorrhea of 5 years duration since her last pregnancy. This pregnancy was complicated by peripartum haemorrhage. As per history, other investigations were done to rule out hypopituitarism. Various serum hormone levels were sent which revealed serum cortisol- 1.11ug/dl (range 5-23ug/dl), serum FSH-2.19mIU/ml (range 36-138mIU/ml), Serum LH-0.6mIU/mi (range 14-48mIU/ml), serum Prolactin-2.99 ng/ml (range 3.1-20.5ng/ml) and serum Estradiol-<10 pg/ml (<30 pg/ml for post-menopausal women); all indicating towards hypopituitarism. MRI brain was suggestive of empty sella (Figure 1). On the background of peripartum haemorrhage the case was labelled as Sheehan syndrome. 

Treatment was started with hormone replacement therapy including steroids and thyroxine. She improved symptomatically with resolution of symptoms and pericardial effusion within 4 weeks. 

Figure 1 (MRI Brain): Yellow arrow showing empty sella (A: T2 weighted, B: T1 weighted).

Hypopituitarism is the partial or complete insufficiency of anterior pituitary hormone secretion and may result from pituitary or hypothalamic disease [1]. In a population-based study of hypopituitarism done in 1998, the prevalence of hypopituitarism was 46 cases per 100,000 individuals and the incidence was 4 cases per 100,000 per year [2]. Accordingly Indian population of 1.2 billion (Census-2011), this will calculate to about 350,000- 555,000 cases of hypopituitarism. Dr. Kochupillai estimated total prevalence of pituitary disorder to 4 million in the year 2000 [3]. Sheehan syndrome is postpartum hypopituitarism caused by necrosis of the pituitary gland. It is one of the most common causes of hypopituitarism in developing countries [4]. Epidemiological study from the Kashmir valley estimated the prevalence to be about 3% for women above 20 years of age, almost two-thirds of whom had delivered babies at home [5]. The pituitary is highly vascular tissues in the body. Its volume increases two-folds during pregnancy; mostly due to the massive hyperplasia of lactotrophs as a result of elevated estrogen secretion. Enlarged pituitary gland is vulnerable to ischemia and does not have the ability to regenerate [6]. Sheehan syndrome can present in the postpartum period or after many months to years following delivery. A study of 60 patients has shown the average time between the previous obstetric event and diagnosis of Sheehan syndrome to be 13 years [7]. 

The diagnosis of Sheehan syndrome is based on history of postpartum hemorrhage followed by complete anterior pituitary failure with demonstration of empty sella on MRI pituitary [6]. In India, around 70% of the population lives in villages. Out of an estimated 25 million deliveries each year, 18 million take place in peripheral areas where maternal and perinatal services are either poor or even non-existent [8]. PPH is a frequent complication of delivery and its incidence is commonly reported as 2-4% after vaginal delivery and 6% after cesarean section with uterine atony being the cause in about 50% cases [8,9]. Thus fairly large number of females can face this problem. 

Among etiologies for tamponade, Merce et al., reported the following incidence rates [10]:

Hypothyroidism is extremely rare cause of Pericardial tamponade. In hypothyroid patients, the causes of effusions are probably increased systemic capillary permeability and disturbances in electrolyte metabolism. The rarity of cardiac tamponade in hypothyroid patients with pericardial effusion is due to the slow accumulation of fluid and the remarkable distensibility of the pericardium. In hypothyroid pericardial effusion, the fluid is straw colored with specific gravity between 1.012 and 1.025. It has a high content of alpha and beta globulins, white blood cells, mainly polymorphs and red blood cells [11]. 

The incidence of Pericardial Effusion in hypothyroidism is 3% to 6% and pericardial tamponade is extremely rare presentation. A case report of pericardial tamponade secondary to primary hypothyroidism in 2011 has stated that, about 20 cases of hypothyroid with cardiac tamponade have been reported in the literature [12]. Even fewer cases of pericardial tamponade secondary to central hypothyroidism are reported, as central hypothyroidism itself is a very rare diagnosis with an estimated prevalence of approximately 1 in 80,000 to 1 in 120,000 making this case extremely rare [13].

As the incidence of peripartum hemorrhage is high in rural India, diagnosed cases of hypopituitarism may only be the iceberg of the disease. As well as, due to higher incidence of tuberculosis in our country there is more liberal empirical use of Anti-Tubercular Treatment (ATT) for pericardial effusion and tamponade. So, whenever there is diagnostic dilemma, before starting ATT, one should have this thought in mind.